1. Field of the Invention
The present invention relates generally to monopole antennas.
2. Description of the Related Art
Military and commercial airborne communication systems have need for exchange of a variety of communication signals (e.g., voice, data, imagery and video) over an extensive ultrabroadband range of signal frequencies (e.g., 30-2000 MHz). Providing antennas for these systems presents some difficult design problems. In the absence of other restrictions, a designer might consider conventional antenna structures (e.g., dipole and monopole antennas) whose dimensions are a significant portion (e.g., one-fourth) of those of the expected signal wavelengths. However, these antenna structures must reliably function over long lifetimes in the hostile environment (e.g., vibration and wind pressure) of high-speed aircraft. The latter requirement requires compact antennas whose dimensions are far less than otherwise desired and whose physical shape will not degrade aircraft performance. Finding ultrabroadband antenna system solutions to these conflicting requirements continues to be a significant challenge.